Furkan Dogan, a 19-year-old high school student who had dual US-Turkish citizenship, was the youngest of those killed in the attack.

IN DEPTH

The US said that it would investigate the Dogan's death, but said the FBI was not involved "at this point".

"We will look into the circumstances of the death of an American citizen, as we would do anywhere in the world at all times," Philip Crowley, a state department spokesman, said.

"We have officials at a variety of levels here and in Israel."

He said the officials were in contact with Israeli authorities and the family of the deceased.

US statement

Joe Biden, the US vice-president, said that Israel had the right to protect its security by boarding the ships.

"I think Israel has an absolute right to deal with its security interest," he said in PBS television interview.

ACTIVISTS KILLED

  Turkish victims
  Ibrahim Bilgen
  Ali Haydar Bengi
  Cevdet Kiliçlar
  Çetin Topçuoglu
  Necdet Yildirim
  Fahri Yaldiz
  Cengiz Songür
  Cengiz Akyüz
  US victim
  Furkan Dogan

He said that Washington, which has branded the situation in Gaza "untenable", would continue to press Israel to improve living conditions for Palestinians under the Gaza siege.

For his part, Abdullah Gul, the Turkish president, said that Israel's raid has caused "irreparable" damage to his country's relations with Israel, and will "never" be forgiven.

"From now on, Turkish-Israeli ties will never be the same. This incident has left an irreparable and deep scar," Gul said to around 20,000 people at the funerals in Istanbul.

A Greek activist said that he saw Israeli troops using laser-guided weapons to shoot people aboard the Mavi Marmara.

Protesters in Greece and Bosnia turned out in their thousands on Friday to demonstrate against Israel's action and to call for an end to the blockade on Gaza.

Israel has remained defiant over the raid, rejecting calls for an international investigation into the incident, and warned that it was ready to intercept another aid ship, the Rachel Corrie, that is expected to reach Gaza on Saturday.